diff --git a/make/lib/Awt2dLibraries.gmk b/make/lib/Awt2dLibraries.gmk
index a06bfd6db047a220cf70ddeb802fec100dcb7f03..9368a9d508c0b9eca42995b17324154e94b34822 100644
--- a/make/lib/Awt2dLibraries.gmk
+++ b/make/lib/Awt2dLibraries.gmk
@@ -658,6 +658,13 @@ endif
 
 ##########################################################################################
 
+ifeq ($(TOOLCHAIN_TYPE), clang)
+ ifeq ($(TOOLCHAIN_VERSION), 10.1)
+   # Work around an optimizer bug seen with Xcode 10.1, but fixed by 10.3
+   BUILD_LIBLCMS_cmsopt.c_CFLAGS := -O0
+ endif
+endif
+
 # TODO: Update awt lib path when awt is converted
 $(eval $(call SetupNativeCompilation,BUILD_LIBLCMS, \
     LIBRARY := lcms, \
diff --git a/src/share/native/sun/java2d/cmm/lcms/cmsps2.c b/src/share/native/sun/java2d/cmm/lcms/cmsps2.c
index a3c7b49dbff25792c781a330aa755b260ec7a368..3f373d808f2fa54be0b99188b3166ac7f0712e0e 100644
--- a/src/share/native/sun/java2d/cmm/lcms/cmsps2.c
+++ b/src/share/native/sun/java2d/cmm/lcms/cmsps2.c
@@ -1443,7 +1443,7 @@ int WriteNamedColorCRD(cmsIOHANDLER* m, cmsHPROFILE hNamedColor, cmsUInt32Number
     cmsUInt32Number i, nColors, nColorant;
     cmsUInt32Number OutputFormat;
     char ColorName[cmsMAX_PATH];
-    char Colorant[128];
+    char Colorant[512];
     cmsNAMEDCOLORLIST* NamedColorList;