diff --git a/libweston/color-management.c b/libweston/color-management.c
index f7478c699..725333d3c 100644
--- a/libweston/color-management.c
+++ b/libweston/color-management.c
@@ -1743,7 +1743,7 @@ weston_compositor_enable_color_management_protocol(struct weston_compositor *com
 
 	weston_assert_bit_is_set(compositor,
 				 compositor->color_manager->supported_rendering_intents,
-				 WESTON_RENDER_INTENT_PERCEPTUAL);
+				 1ull << WESTON_RENDER_INTENT_PERCEPTUAL);
 
 	if (!wl_global_create(compositor->wl_display,
 			      &wp_color_manager_v1_interface,
diff --git a/shared/helpers.h b/shared/helpers.h
index 7ff60d03e..42f75e35d 100644
--- a/shared/helpers.h
+++ b/shared/helpers.h
@@ -25,6 +25,7 @@
 #include "config.h"
 
 #include <stdint.h>
+#include <stdbool.h>
 
 #ifdef  __cplusplus
 extern "C" {
@@ -284,6 +285,18 @@ bswap32(uint32_t x)
 #endif
 }
 
+/**
+ * Returns whether 64-bit value x is a power of 2.
+ *
+ * @param x a 64-bit value.
+ * @return true if x is a power of 2.
+ */
+static inline bool
+is_pow2_64(uint64_t x)
+{
+	return (x & (x - 1)) == 0;
+}
+
 /**
  * Returns the highest power of two lesser than or equal to 32-bit value x.
  * Saturated to 0 (which isn't a power of two) if x is lesser than 2^0.
diff --git a/shared/weston-assert.h b/shared/weston-assert.h
index e8d39a552..5d2fa2491 100644
--- a/shared/weston-assert.h
+++ b/shared/weston-assert.h
@@ -125,10 +125,11 @@ do {										\
 ({										\
 	struct weston_compositor *ec = compositor;				\
 	uint64_t v = (value);							\
-	uint8_t b = (bit);							\
-	bool cond = (v >> b) & 1;						\
+	uint64_t b = (bit);							\
+	bool cond = (v & b) == b;						\
+	weston_assert_true(compositor, is_pow2_64(bit));			\
 	if (!cond)								\
-		custom_assert_fail_(ec, "%s:%u: Assertion failed! Bit %s (%u) of %s (0x%" PRIx64 ") is not set.\n",	\
+		custom_assert_fail_(ec, "%s:%u: Assertion failed! Bit \"%s\" (%" PRIu64 ") of \"%s\" (0x%" PRIx64 ") is not set.\n",	\
 				    __FILE__, __LINE__, #bit, b, #value, v);	\
 	cond;									\
 })
@@ -137,10 +138,11 @@ do {										\
 ({										\
 	struct weston_compositor *ec = compositor;				\
 	uint64_t v = (value);							\
-	uint8_t b = (bit);							\
-	bool cond = (v >> b) & 1;						\
-	if (cond)								\
-		custom_assert_fail_(ec, "%s:%u: Assertion failed! Bit %s (%u) of %s (0x%" PRIx64 ") is set.\n",	\
+	uint64_t b = (bit);							\
+	bool cond = (v & b) == 0;						\
+	weston_assert_true(compositor, is_pow2_64(bit));			\
+	if (!cond)								\
+		custom_assert_fail_(ec, "%s:%u: Assertion failed! Bit \"%s\" (%" PRIu64 ") of \"%s\" (0x%" PRIx64 ") is set.\n",	\
 				    __FILE__, __LINE__, #bit, b, #value, v);	\
 	cond;									\
 })
diff --git a/tests/assert-test.c b/tests/assert-test.c
index 011dacb70..42736fbd4 100644
--- a/tests/assert-test.c
+++ b/tests/assert-test.c
@@ -134,9 +134,9 @@ TEST(asserts)
 	abort_if_not(ret == false);
 
 	uint32_t bitfield = 0xffff;
-	ret = weston_assert_bit_is_set(compositor, bitfield, 2);
+	ret = weston_assert_bit_is_set(compositor, bitfield, 1ull << 2);
 	abort_if_not(ret);
-	ret = weston_assert_bit_is_set(compositor, bitfield, 57);
+	ret = weston_assert_bit_is_set(compositor, bitfield, 1ull << 57);
 	abort_if_not(ret == false);
 
 	uint64_t max_uint64 = UINT64_MAX;