diff --git a/build/toolchain.afl.mak b/build/toolchain.afl.mak
index 28fa52426..63b4e0002 100644
--- a/build/toolchain.afl.mak
+++ b/build/toolchain.afl.mak
@@ -6,3 +6,7 @@ LD = afl-clang++
 ifeq ($(ASAN),1)
 export AFL_USE_ASAN = 1
 endif
+
+# Prevent NDEBUG from being defined since we will always want assertions to run
+# when the code is being fuzzed
+SFLAGS := $(filter-out -DNDEBUG,$(SFLAGS))