diff --git a/include/rcutils/time.h b/include/rcutils/time.h
index ec9ed523..e08692fa 100644
--- a/include/rcutils/time.h
+++ b/include/rcutils/time.h
@@ -27,18 +27,18 @@ extern "C"
 #include "rcutils/visibility_control.h"
 
 /// Convenience macro to convert seconds to nanoseconds.
-#define RCUTILS_S_TO_NS(seconds) (seconds * (1000 * 1000 * 1000))
+#define RCUTILS_S_TO_NS(seconds) (seconds * (1000LL * 1000LL * 1000LL))
 /// Convenience macro to convert milliseconds to nanoseconds.
-#define RCUTILS_MS_TO_NS(milliseconds) (milliseconds * (1000 * 1000))
+#define RCUTILS_MS_TO_NS(milliseconds) (milliseconds * (1000LL * 1000LL))
 /// Convenience macro to convert microseconds to nanoseconds.
-#define RCUTILS_US_TO_NS(microseconds) (microseconds * 1000)
+#define RCUTILS_US_TO_NS(microseconds) (microseconds * 1000LL)
 
 /// Convenience macro to convert nanoseconds to seconds.
-#define RCUTILS_NS_TO_S(nanoseconds) (nanoseconds / (1000 * 1000 * 1000))
+#define RCUTILS_NS_TO_S(nanoseconds) (nanoseconds / (1000LL * 1000LL * 1000LL))
 /// Convenience macro to convert nanoseconds to milliseconds.
-#define RCUTILS_NS_TO_MS(nanoseconds) (nanoseconds / (1000 * 1000))
+#define RCUTILS_NS_TO_MS(nanoseconds) (nanoseconds / (1000LL * 1000LL))
 /// Convenience macro to convert nanoseconds to microseconds.
-#define RCUTILS_NS_TO_US(nanoseconds) (nanoseconds / 1000)
+#define RCUTILS_NS_TO_US(nanoseconds) (nanoseconds / 1000LL)
 
 /// A single point in time, measured in nanoseconds since the Unix epoch.
 typedef int64_t rcutils_time_point_value_t;