diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -121,18 +121,15 @@
 endif()
 
 # Enable warning
-add_c_compiler_flag(-Wnested-externs -Wstrict-prototypes)
 add_compiler_flag(
 	-Wall
 	-Wextra
 	-Wformat
 	-Wvla
 	-Wformat-security
-	-Wcast-align
 	-Wunused-parameter
 	-Wmissing-braces
-	# FIXME: Activating this flag cause cmake to fail on leveldb.
-	# -Wthread-safety-analysis
+	-Wthread-safety-analysis
 	-Wshadow
 )
 
diff --git a/src/secp256k1/CMakeLists.txt b/src/secp256k1/CMakeLists.txt
--- a/src/secp256k1/CMakeLists.txt
+++ b/src/secp256k1/CMakeLists.txt
@@ -6,15 +6,16 @@
 # libsecp256k1 use a different set of flags.
 add_compiler_flag(
 	-pedantic
-	-Wshadow
+	-Wcast-align
 	-Wno-unused-function
-	-Wno-nonnull
 	-Wno-overlength-strings
 )
 
 add_c_compiler_flag(
 	-std=c89
 	-Wno-long-long
+	-Wnested-externs
+	-Wstrict-prototypes
 )
 
 # Default visibility is hidden on all targets.