Index: src/OFDate.m
==================================================================
--- src/OFDate.m
+++ src/OFDate.m
@@ -359,16 +359,16 @@
 
 	[element addChild:
 	    [OFXMLElement elementWithName: @"seconds"
 				namespace: OF_SERIALIZATION_NS
 			      stringValue: [OFString stringWithFormat:
-					       @"%" PRId64, seconds]]];
+					       @"%" @PRId64, seconds]]];
 	[element addChild:
 	    [OFXMLElement elementWithName: @"microseconds"
 				namespace: OF_SERIALIZATION_NS
 			      stringValue: [OFString stringWithFormat:
-					       @"%" PRIu32, microseconds]]];
+					       @"%" @PRIu32, microseconds]]];
 
 	[pool release];
 
 	return element;
 }

Index: src/of_asprintf.m
==================================================================
--- src/of_asprintf.m
+++ src/of_asprintf.m
@@ -170,12 +170,17 @@
 
 		break;
 	case 'l': /* and also ll */
 		if (ctx->formatLen > ctx->i + 1 &&
 		    ctx->format[ctx->i + 1] == 'l') {
+#ifndef _WIN32
 			if (!appendSubformat(ctx, ctx->format + ctx->i, 2))
 				return false;
+#else
+			if (!appendSubformat(ctx, "I64", 3))
+				return false;
+#endif
 
 			ctx->i++;
 			ctx->lengthModifier = LENGTH_MODIFIER_LL;
 		} else {
 			if (!appendSubformat(ctx, ctx->format + ctx->i, 1))
@@ -184,12 +189,17 @@
 			ctx->lengthModifier = LENGTH_MODIFIER_L;
 		}
 
 		break;
 	case 'j':
+#ifndef _WIN32
 		if (!appendSubformat(ctx, ctx->format + ctx->i, 1))
 			return false;
+#else
+		if (!appendSubformat(ctx, "I64", 3))
+			return false;
+#endif
 
 		ctx->lengthModifier = LENGTH_MODIFIER_J;
 
 		break;
 	case 'z':
@@ -211,10 +221,25 @@
 			return false;
 
 		ctx->lengthModifier = LENGTH_MODIFIER_CAPITAL_L;
 
 		break;
+#ifdef _WIN32
+	case 'I': /* win32 strangeness (I64 instead of ll or j) */
+		if (ctx->formatLen > ctx->i + 2 &&
+		    ctx->format[ctx->i + 1] == '6' &&
+		    ctx->format[ctx->i + 2] == '4') {
+			if (!appendSubformat(ctx, ctx->format + ctx->i, 3))
+				return false;
+
+			ctx->i += 2;
+			ctx->lengthModifier = LENGTH_MODIFIER_LL;
+		} else
+			ctx->i--;
+
+		break;
+#endif
 	default:
 		ctx->i--;
 
 		break;
 	}