diff --git a/Android.mk b/Android.mk
index 8eaf4e5..72eca2b 100644
--- a/Android.mk
+++ b/Android.mk
@@ -55,7 +55,8 @@
 	-O3 \
 	-Wno-implicit-function-declaration \
 	-Wno-strict-aliasing \
-	-Wno-unused-parameter
+	-Wno-unused-parameter \
+	-Werror
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := libevent
diff --git a/include/event2/event-config-darwin.h b/include/event2/event-config-darwin.h
index 06ecd0f..4d4e239 100644
--- a/include/event2/event-config-darwin.h
+++ b/include/event2/event-config-darwin.h
@@ -10,6 +10,18 @@
 
 #ifndef _EVENT2_EVENT_CONFIG_H_
 #define _EVENT2_EVENT_CONFIG_H_
+
+#include <stdint.h>
+
+/* The size of `size_t', as computed by sizeof. */
+#if SIZE_MAX == UINT64_MAX
+#  define _EVENT_SIZEOF_SIZE_T 8
+#elif SIZE_MAX == UINT32_MAX
+#  define _EVENT_SIZEOF_SIZE_T 4
+#else
+#  error "No way to infer sizeof size_t"
+#endif
+
 /* config.h.  Generated from config.h.in by configure.  */
 /* config.h.in.  Generated from configure.ac by autoheader.  */
 
@@ -415,9 +427,6 @@
 /* The size of `short', as computed by sizeof. */
 #define _EVENT_SIZEOF_SHORT 2
 
-/* The size of `size_t', as computed by sizeof. */
-#define _EVENT_SIZEOF_SIZE_T 8
-
 /* The size of `void *', as computed by sizeof. */
 #define _EVENT_SIZEOF_VOID_P 8
 
diff --git a/include/event2/event-config-linux.h b/include/event2/event-config-linux.h
index 60a0855..5a906df 100644
--- a/include/event2/event-config-linux.h
+++ b/include/event2/event-config-linux.h
@@ -11,6 +11,17 @@
 #ifndef _EVENT2_EVENT_CONFIG_H_
 #define _EVENT2_EVENT_CONFIG_H_
 
+#include <stdint.h>
+
+/* The size of `size_t', as computed by sizeof. */
+#if SIZE_MAX == UINT64_MAX
+#  define _EVENT_SIZEOF_SIZE_T 8
+#elif SIZE_MAX == UINT32_MAX
+#  define _EVENT_SIZEOF_SIZE_T 4
+#else
+#  error "No way to infer sizeof size_t"
+#endif
+
 /* config.h.  Generated from config.h.in by configure.  */
 /* config.h.in.  Generated from configure.ac by autoheader.  */
 
@@ -416,9 +427,6 @@
 /* The size of `short', as computed by sizeof. */
 #define _EVENT_SIZEOF_SHORT 2
 
-/* The size of `size_t', as computed by sizeof. */
-#define _EVENT_SIZEOF_SIZE_T 8
-
 /* The size of `void *', as computed by sizeof. */
 #define _EVENT_SIZEOF_VOID_P 8