diff --git a/Makefile b/Makefile
index 933d7c6..74a840e 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,7 @@ PERL=perl
 CFLAGS ?= -O2
 PICFLAG = -fPIC
 C99FLAG = -std=c99
-WCFLAGS = -Wsign-conversion -Wall -Wextra -pedantic
+WCFLAGS = -Wsign-conversion -Wall -Wextra -Wc++-compat -pedantic
 UCFLAGS = $(CPPFLAGS) $(CFLAGS) $(PICFLAG) $(C99FLAG) $(WCFLAGS) -DUTF8PROC_EXPORTS $(UTF8PROC_DEFINES)
 LDFLAG_SHARED = -shared
 SOFLAG = -Wl,-soname
diff --git a/utf8proc.c b/utf8proc.c
index 87cec94..40ea295 100644
--- a/utf8proc.c
+++ b/utf8proc.c
@@ -447,7 +447,7 @@ UTF8PROC_DLLEXPORT const char *utf8proc_category_string(utf8proc_int32_t c) {
 
 #define utf8proc_decompose_lump(replacement_uc) \
   return utf8proc_decompose_char((replacement_uc), dst, bufsize, \
-  options & ~(unsigned int)UTF8PROC_LUMP, last_boundclass)
+  (utf8proc_option_t)(options & ~(unsigned int)UTF8PROC_LUMP), last_boundclass)
 
 UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose_char(utf8proc_int32_t uc, utf8proc_int32_t *dst, utf8proc_ssize_t bufsize, utf8proc_option_t options, int *last_boundclass) {
   const utf8proc_property_t *property;
@@ -790,35 +790,35 @@ UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_map_custom(
 
 UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFD(const utf8proc_uint8_t *str) {
   utf8proc_uint8_t *retval;
-  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |
-    UTF8PROC_DECOMPOSE);
+  utf8proc_map(str, 0, &retval, (utf8proc_option_t)(UTF8PROC_NULLTERM | UTF8PROC_STABLE |
+    UTF8PROC_DECOMPOSE));
   return retval;
 }
 
 UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFC(const utf8proc_uint8_t *str) {
   utf8proc_uint8_t *retval;
-  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |
-    UTF8PROC_COMPOSE);
+  utf8proc_map(str, 0, &retval, (utf8proc_option_t)(UTF8PROC_NULLTERM | UTF8PROC_STABLE |
+    UTF8PROC_COMPOSE));
   return retval;
 }
 
 UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKD(const utf8proc_uint8_t *str) {
   utf8proc_uint8_t *retval;
-  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |
-    UTF8PROC_DECOMPOSE | UTF8PROC_COMPAT);
+  utf8proc_map(str, 0, &retval, (utf8proc_option_t)(UTF8PROC_NULLTERM | UTF8PROC_STABLE |
+    UTF8PROC_DECOMPOSE | UTF8PROC_COMPAT));
   return retval;
 }
 
 UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC(const utf8proc_uint8_t *str) {
   utf8proc_uint8_t *retval;
-  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |
-    UTF8PROC_COMPOSE | UTF8PROC_COMPAT);
+  utf8proc_map(str, 0, &retval, (utf8proc_option_t)(UTF8PROC_NULLTERM | UTF8PROC_STABLE |
+    UTF8PROC_COMPOSE | UTF8PROC_COMPAT));
   return retval;
 }
 
 UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC_Casefold(const utf8proc_uint8_t *str) {
   utf8proc_uint8_t *retval;
-  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |
-    UTF8PROC_COMPOSE | UTF8PROC_COMPAT | UTF8PROC_CASEFOLD | UTF8PROC_IGNORE);
+  utf8proc_map(str, 0, &retval, (utf8proc_option_t)(UTF8PROC_NULLTERM | UTF8PROC_STABLE |
+    UTF8PROC_COMPOSE | UTF8PROC_COMPAT | UTF8PROC_CASEFOLD | UTF8PROC_IGNORE));
   return retval;
 }