diff --git a/generic/tclDisassemble.c b/generic/tclDisassemble.c
index ee8da033e9c..c2dd58dd9c8 100644
--- a/generic/tclDisassemble.c
+++ b/generic/tclDisassemble.c
@@ -279,7 +279,7 @@ DisassembleByteCodeObj(
      */
 
     Tcl_AppendPrintfToObj(bufferObj,
-	    "ByteCode %p, refCt %" TCL_SIZE_MODIFIER "u, epoch %" TCL_SIZE_MODIFIER "u, interp %p (epoch %" TCL_SIZE_MODIFIER "u)\n",
+	    "ByteCode %p, refCt %" TCL_SIZE_MODIFIER "d, epoch %" TCL_SIZE_MODIFIER "d, interp %p (epoch %" TCL_SIZE_MODIFIER "d)\n",
 	    codePtr, codePtr->refCount, codePtr->compileEpoch, iPtr, iPtr->compileEpoch);
     Tcl_AppendToObj(bufferObj, "  Source ", -1);
     PrintSourceToObj(bufferObj, codePtr->source,
@@ -290,7 +290,7 @@ DisassembleByteCodeObj(
 		TclGetString(fileObj), line);
     }
     Tcl_AppendPrintfToObj(bufferObj,
-	    "\n  Cmds %d, src %" TCL_SIZE_MODIFIER "u, inst %" TCL_SIZE_MODIFIER "u, litObjs %" TCL_SIZE_MODIFIER "u, aux %" TCL_SIZE_MODIFIER "u, stkDepth %" TCL_SIZE_MODIFIER "u, code/src %.2f\n",
+	    "\n  Cmds %d, src %" TCL_SIZE_MODIFIER "d, inst %" TCL_SIZE_MODIFIER "d, litObjs %" TCL_SIZE_MODIFIER "d, aux %" TCL_SIZE_MODIFIER "d, stkDepth %" TCL_SIZE_MODIFIER "d, code/src %.2f\n",
 	    numCmds, codePtr->numSrcBytes, codePtr->numCodeBytes,
 	    codePtr->numLitObjects, codePtr->numAuxDataItems,
 	    codePtr->maxStackDepth,
@@ -302,8 +302,8 @@ DisassembleByteCodeObj(
 
 #ifdef TCL_COMPILE_STATS
     Tcl_AppendPrintfToObj(bufferObj,
-	    "  Code %" TCL_Z_MODIFIER "u = header %" TCL_Z_MODIFIER "u+inst %" TCL_SIZE_MODIFIER "u+litObj %"
-	    TCL_Z_MODIFIER "u+exc %" TCL_Z_MODIFIER "u+aux %" TCL_Z_MODIFIER "u+cmdMap %" TCL_SIZE_MODIFIER "u\n",
+	    "  Code %" TCL_Z_MODIFIER "u = header %" TCL_Z_MODIFIER "u+inst %" TCL_SIZE_MODIFIER "d+litObj %"
+	    TCL_Z_MODIFIER "u+exc %" TCL_Z_MODIFIER "u+aux %" TCL_Z_MODIFIER "u+cmdMap %" TCL_SIZE_MODIFIER "d\n",
 	    codePtr->structureSize,
 	    offsetof(ByteCode, localCachePtr),
 	    codePtr->numCodeBytes,
@@ -324,7 +324,7 @@ DisassembleByteCodeObj(
 	Tcl_Size numCompiledLocals = procPtr->numCompiledLocals;
 
 	Tcl_AppendPrintfToObj(bufferObj,
-		"  Proc %p, refCt %" TCL_SIZE_MODIFIER "u, args %" TCL_SIZE_MODIFIER "u, compiled locals %" TCL_SIZE_MODIFIER "u\n",
+		"  Proc %p, refCt %" TCL_SIZE_MODIFIER "d, args %" TCL_SIZE_MODIFIER "d, compiled locals %" TCL_SIZE_MODIFIER "d\n",
 		procPtr, procPtr->refCount, procPtr->numArgs,
 		numCompiledLocals);
 	if (numCompiledLocals > 0) {
@@ -332,7 +332,7 @@ DisassembleByteCodeObj(
 
 	    for (i = 0;  i < numCompiledLocals;  i++) {
 		Tcl_AppendPrintfToObj(bufferObj,
-			"      slot %" TCL_SIZE_MODIFIER "u%s%s%s%s%s%s", i,
+			"      slot %" TCL_SIZE_MODIFIER "d%s%s%s%s%s%s", i,
 			(localPtr->flags & (VAR_ARRAY|VAR_LINK)) ? "" : ", scalar",
 			(localPtr->flags & VAR_ARRAY) ? ", array" : "",
 			(localPtr->flags & VAR_LINK) ? ", link" : "",
@@ -355,24 +355,24 @@ DisassembleByteCodeObj(
      */
 
     if ((int)codePtr->numExceptRanges > 0) {
-	Tcl_AppendPrintfToObj(bufferObj, "  Exception ranges %" TCL_SIZE_MODIFIER "u, depth %" TCL_SIZE_MODIFIER "u:\n",
+	Tcl_AppendPrintfToObj(bufferObj, "  Exception ranges %" TCL_SIZE_MODIFIER "d, depth %" TCL_SIZE_MODIFIER "d:\n",
 		codePtr->numExceptRanges, codePtr->maxExceptDepth);
 	for (i = 0;  i < (int)codePtr->numExceptRanges;  i++) {
 	    ExceptionRange *rangePtr = &codePtr->exceptArrayPtr[i];
 
 	    Tcl_AppendPrintfToObj(bufferObj,
-		    "      %" TCL_SIZE_MODIFIER "u: level %" TCL_SIZE_MODIFIER "u, %s, pc %" TCL_SIZE_MODIFIER "u-%" TCL_SIZE_MODIFIER "u, ",
+		    "      %" TCL_SIZE_MODIFIER "d: level %" TCL_SIZE_MODIFIER "d, %s, pc %" TCL_SIZE_MODIFIER "d-%" TCL_SIZE_MODIFIER "d, ",
 		    i, rangePtr->nestingLevel,
 		    (rangePtr->type==LOOP_EXCEPTION_RANGE ? "loop" : "catch"),
 		    rangePtr->codeOffset,
 		    (rangePtr->codeOffset + rangePtr->numCodeBytes - 1));
 	    switch (rangePtr->type) {
 	    case LOOP_EXCEPTION_RANGE:
-		Tcl_AppendPrintfToObj(bufferObj, "continue %" TCL_SIZE_MODIFIER "u, break %" TCL_SIZE_MODIFIER "u\n",
+		Tcl_AppendPrintfToObj(bufferObj, "continue %" TCL_SIZE_MODIFIER "d, break %" TCL_SIZE_MODIFIER "d\n",
 			rangePtr->continueOffset, rangePtr->breakOffset);
 		break;
 	    case CATCH_EXCEPTION_RANGE:
-		Tcl_AppendPrintfToObj(bufferObj, "catch %" TCL_SIZE_MODIFIER "u\n",
+		Tcl_AppendPrintfToObj(bufferObj, "catch %" TCL_SIZE_MODIFIER "d\n",
 			rangePtr->catchOffset);
 		break;
 	    default:
@@ -446,7 +446,7 @@ DisassembleByteCodeObj(
 	    srcLengthNext++;
 	}
 
-	Tcl_AppendPrintfToObj(bufferObj, "%s%4" TCL_SIZE_MODIFIER "u: pc %d-%d, src %d-%d",
+	Tcl_AppendPrintfToObj(bufferObj, "%s%4" TCL_SIZE_MODIFIER "d: pc %d-%d, src %d-%d",
 		((i % 2)? "     " : "\n   "),
 		(i+1), codeOffset, (codeOffset + codeLen - 1),
 		srcOffset, (srcOffset + srcLen - 1));
@@ -505,7 +505,7 @@ DisassembleByteCodeObj(
 	    pc += FormatInstruction(codePtr, pc, bufferObj);
 	}
 
-	Tcl_AppendPrintfToObj(bufferObj, "  Command %" TCL_SIZE_MODIFIER "u: ", i+1);
+	Tcl_AppendPrintfToObj(bufferObj, "  Command %" TCL_SIZE_MODIFIER "d: ", i+1);
 	PrintSourceToObj(bufferObj, (codePtr->source + srcOffset),
 		TclMin(srcLen, 55));
 	Tcl_AppendToObj(bufferObj, "\n", -1);
@@ -626,7 +626,7 @@ FormatInstruction(
 	printLVTindex:
 	    if (localPtr != NULL) {
 		if (opnd >= localCt) {
-		    Tcl_Panic("FormatInstruction: bad local var index %u (%" TCL_SIZE_MODIFIER "u locals)",
+		    Tcl_Panic("FormatInstruction: bad local var index %u (%" TCL_SIZE_MODIFIER "d locals)",
 			    opnd, localCt);
 		}
 		for (j = 0;  j < opnd;  j++) {
@@ -1147,14 +1147,14 @@ DisassembleByteCodeAsDicts(
 	switch (rangePtr->type) {
 	case LOOP_EXCEPTION_RANGE:
 	    Tcl_ListObjAppendElement(NULL, exn, Tcl_ObjPrintf(
-		    "type %s level %" TCL_SIZE_MODIFIER "u from %" TCL_SIZE_MODIFIER "u to %" TCL_SIZE_MODIFIER "u break %" TCL_SIZE_MODIFIER "u continue %" TCL_SIZE_MODIFIER "u",
+		    "type %s level %" TCL_SIZE_MODIFIER "d from %" TCL_SIZE_MODIFIER "d to %" TCL_SIZE_MODIFIER "d break %" TCL_SIZE_MODIFIER "d continue %" TCL_SIZE_MODIFIER "d",
 		    "loop", rangePtr->nestingLevel, rangePtr->codeOffset,
 		    rangePtr->codeOffset + rangePtr->numCodeBytes - 1,
 		    rangePtr->breakOffset, rangePtr->continueOffset));
 	    break;
 	case CATCH_EXCEPTION_RANGE:
 	    Tcl_ListObjAppendElement(NULL, exn, Tcl_ObjPrintf(
-		    "type %s level %" TCL_SIZE_MODIFIER "u from %" TCL_SIZE_MODIFIER "u to %" TCL_SIZE_MODIFIER "u catch %" TCL_SIZE_MODIFIER "u",
+		    "type %s level %" TCL_SIZE_MODIFIER "d from %" TCL_SIZE_MODIFIER "d to %" TCL_SIZE_MODIFIER "d catch %" TCL_SIZE_MODIFIER "d",
 		    "catch", rangePtr->nestingLevel, rangePtr->codeOffset,
 		    rangePtr->codeOffset + rangePtr->numCodeBytes - 1,
 		    rangePtr->catchOffset));
diff --git a/generic/tclEncoding.c b/generic/tclEncoding.c
index 45c08da4502..c211dfb08ac 100644
--- a/generic/tclEncoding.c
+++ b/generic/tclEncoding.c
@@ -1249,11 +1249,11 @@ Tcl_ExternalToUtfDStringEx(
 		/* Caller wants error message on failure */
 		if (result != TCL_OK && interp != NULL) {
 		    char buf[TCL_INTEGER_SPACE];
-		    snprintf(buf, sizeof(buf), "%" TCL_SIZE_MODIFIER "u", nBytesProcessed);
+		    snprintf(buf, sizeof(buf), "%" TCL_SIZE_MODIFIER "d", nBytesProcessed);
 		    Tcl_SetObjResult(
 			interp,
 			Tcl_ObjPrintf("unexpected byte sequence starting at index %"
-				      TCL_SIZE_MODIFIER "u: '\\x%02X'",
+				      TCL_SIZE_MODIFIER "d: '\\x%02X'",
 				      nBytesProcessed,
 				      UCHAR(srcStart[nBytesProcessed])));
 		    Tcl_SetErrorCode(
@@ -1582,7 +1582,7 @@ Tcl_UtfToExternalDStringEx(
 		    int ucs4;
 		    char buf[TCL_INTEGER_SPACE];
 		    Tcl_UtfToUniChar(&srcStart[nBytesProcessed], &ucs4);
-		    snprintf(buf, sizeof(buf), "%" TCL_SIZE_MODIFIER "u", nBytesProcessed);
+		    snprintf(buf, sizeof(buf), "%" TCL_SIZE_MODIFIER "d", nBytesProcessed);
 		    Tcl_SetObjResult(
 			interp,
 			Tcl_ObjPrintf(
diff --git a/generic/tclIORChan.c b/generic/tclIORChan.c
index 4a86c11e43f..e8ce5f1acce 100644
--- a/generic/tclIORChan.c
+++ b/generic/tclIORChan.c
@@ -2014,7 +2014,7 @@ ReflectGetOption(
 	Tcl_ResetResult(interp);
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
 		"Expected list with even number of "
-		"elements, got %" TCL_SIZE_MODIFIER "u element%s instead", listc,
+		"elements, got %" TCL_SIZE_MODIFIER "d element%s instead", listc,
 		(listc == 1 ? "" : "s")));
         goto error;
     } else {
@@ -3323,7 +3323,7 @@ ForwardProc(
 
 		char *buf = (char *)Tcl_Alloc(200);
 		snprintf(buf, 200,
-			"{Expected list with even number of elements, got %" TCL_SIZE_MODIFIER "u %s instead}",
+			"{Expected list with even number of elements, got %" TCL_SIZE_MODIFIER "d %s instead}",
 			listc, (listc == 1 ? "element" : "elements"));
 
 		ForwardSetDynamicError(paramPtr, buf);
diff --git a/generic/tclListObj.c b/generic/tclListObj.c
index 4b3d178ce7d..4b67f984d03 100644
--- a/generic/tclListObj.c
+++ b/generic/tclListObj.c
@@ -3169,7 +3169,7 @@ TclListObjSetElement(
     if ((index < 0) || (index >= elemCount)) {
 	if (interp != NULL) {
 		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-			"index \"%" TCL_SIZE_MODIFIER "u\" out of range", index));
+			"index \"%" TCL_SIZE_MODIFIER "d\" out of range", index));
 	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "INDEX",
 		    "OUTOFRANGE", (void *)NULL);
 	}
diff --git a/generic/tclProc.c b/generic/tclProc.c
index daf82841bc4..01c7611dbb6 100644
--- a/generic/tclProc.c
+++ b/generic/tclProc.c
@@ -496,8 +496,8 @@ TclCreateProc(
     if (precompiled) {
 	if (numArgs > procPtr->numArgs) {
 	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-		    "procedure \"%s\": arg list contains %" TCL_SIZE_MODIFIER "u entries, "
-		    "precompiled header expects %" TCL_SIZE_MODIFIER "u", procName, numArgs,
+		    "procedure \"%s\": arg list contains %" TCL_SIZE_MODIFIER "d entries, "
+		    "precompiled header expects %" TCL_SIZE_MODIFIER "d", procName, numArgs,
 		    procPtr->numArgs));
 	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PROC",
 		    "BYTECODELIES", (void *)NULL);
@@ -591,7 +591,7 @@ TclCreateProc(
 		    || (localPtr->defValuePtr == NULL && fieldCount == 2)
 		    || (localPtr->defValuePtr != NULL && fieldCount != 2)) {
 		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
-			"procedure \"%s\": formal parameter %" TCL_SIZE_MODIFIER "u is "
+			"procedure \"%s\": formal parameter %" TCL_SIZE_MODIFIER "d is "
 			"inconsistent with precompiled body", procName, i));
 		Tcl_SetErrorCode(interp, "TCL", "OPERATION", "PROC",
 			"BYTECODELIES", (void *)NULL);