diff --git a/libc/Android.mk b/libc/Android.mk
index 4b81f7e46..2ec12811c 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -568,6 +568,7 @@ LOCAL_CFLAGS += -DTM_GMTOFF=tm_gmtoff
 LOCAL_CFLAGS += -DTZDIR=\"/system/usr/share/zoneinfo\"
 # Include timezone and daylight globals.
 LOCAL_CFLAGS += -DUSG_COMPAT=1
+LOCAL_CFLAGS += -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
 
 LOCAL_CONLYFLAGS := $(libc_common_conlyflags)
 LOCAL_CPPFLAGS := $(libc_common_cppflags)
@@ -618,6 +619,7 @@ include $(CLEAR_VARS)
 LOCAL_SRC_FILES := $(libc_upstream_freebsd_src_files)
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
+    -Wno-sign-compare -Wno-uninitialized \
     -I$(LOCAL_PATH)/upstream-freebsd/android/include \
     -I$(LOCAL_PATH)/upstream-freebsd/lib/libc/include \
     -include freebsd-compat.h
@@ -644,6 +646,7 @@ include $(CLEAR_VARS)
 LOCAL_SRC_FILES := $(libc_upstream_netbsd_src_files)
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
+    -Wno-sign-compare -Wno-uninitialized \
     -DPOSIX_MISTAKE \
     -I$(LOCAL_PATH)/upstream-netbsd/android/include \
     -I$(LOCAL_PATH)/upstream-netbsd/lib/libc/include \
@@ -671,6 +674,7 @@ include $(CLEAR_VARS)
 LOCAL_SRC_FILES := $(libc_upstream_openbsd_src_files)
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
+    -Wno-sign-compare -Wno-uninitialized \
     -I$(LOCAL_PATH)/upstream-openbsd/android/include \
     -I$(LOCAL_PATH)/upstream-openbsd/lib/libc/include \
     -I$(LOCAL_PATH)/upstream-openbsd/lib/libc/gdtoa/ \
@@ -699,6 +703,7 @@ LOCAL_SRC_FILES_32 := $(libc_upstream_openbsd_gdtoa_src_files_32)
 LOCAL_SRC_FILES_64 := $(libc_upstream_openbsd_gdtoa_src_files_64)
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
+    -Wno-sign-compare -Wno-uninitialized \
     -fvisibility=hidden \
     -I$(LOCAL_PATH)/upstream-openbsd/android/include \
     -I$(LOCAL_PATH)/upstream-openbsd/lib/libc/include \
diff --git a/libc/tzcode/strftime.c b/libc/tzcode/strftime.c
index 2a1db6422..967629de6 100644
--- a/libc/tzcode/strftime.c
+++ b/libc/tzcode/strftime.c
@@ -160,7 +160,7 @@ const struct strftime_locale *locale;
     tzset();
     warn = IN_NONE;
     p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, locale);
-#if 0  /* ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
+#ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
     if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
         (void) fprintf(stderr, "\n");
         if (format == NULL)
diff --git a/libc/upstream-openbsd/android/include/openbsd-compat.h b/libc/upstream-openbsd/android/include/openbsd-compat.h
index b55f39050..bacd1d7dd 100644
--- a/libc/upstream-openbsd/android/include/openbsd-compat.h
+++ b/libc/upstream-openbsd/android/include/openbsd-compat.h
@@ -17,7 +17,6 @@
 #ifndef _BIONIC_OPENBSD_COMPAT_H_included
 #define _BIONIC_OPENBSD_COMPAT_H_included
 
-#define _GNU_SOURCE
 #define __USE_BSD
 
 /* OpenBSD's <ctype.h> uses these names, which conflicted with stlport.
diff --git a/libm/Android.mk b/libm/Android.mk
index 5f69d1ef1..d7d8bc1e9 100644
--- a/libm/Android.mk
+++ b/libm/Android.mk
@@ -234,6 +234,11 @@ libm_common_cflags := \
     -DFLT_EVAL_METHOD=0 \
     -std=c99 \
     -include $(LOCAL_PATH)/freebsd-compat.h \
+    -Wno-missing-braces \
+    -Wno-parentheses \
+    -Wno-sign-compare \
+    -Wno-uninitialized \
+    -Wno-unknown-pragmas \
 
 libm_common_includes := $(LOCAL_PATH)/upstream-freebsd/lib/msun/src/
 
diff --git a/libm/include/math.h b/libm/include/math.h
index bd0241b36..4d174f931 100644
--- a/libm/include/math.h
+++ b/libm/include/math.h
@@ -396,16 +396,23 @@ float	significandf(float);
  * long double versions of ISO/POSIX math functions
  */
 #if __ISO_C_VISIBLE >= 1999
+long double	acoshl(long double);
 long double	acosl(long double);
+long double	asinhl(long double);
 long double	asinl(long double);
 long double	atan2l(long double, long double);
+long double	atanhl(long double);
 long double	atanl(long double);
 long double	cbrtl(long double);
 long double	ceill(long double);
 long double	copysignl(long double, long double) __pure2;
+long double	coshl(long double);
 long double	cosl(long double);
+long double	erfcl(long double);
+long double	erfl(long double);
 long double	exp2l(long double);
 long double	expl(long double);
+long double	expm1l(long double);
 long double	fabsl(long double) __pure2;
 long double	fdiml(long double, long double);
 long double	floorl(long double);
@@ -417,9 +424,14 @@ long double	frexpl(long double value, int *); /* fundamentally !__pure2 */
 long double	hypotl(long double, long double);
 int		ilogbl(long double) __pure2;
 long double	ldexpl(long double, int);
+long double	lgammal(long double);
 long long	llrintl(long double);
 long long	llroundl(long double);
+long double	log10l(long double);
+long double	log1pl(long double);
+long double	log2l(long double);
 long double	logbl(long double);
+long double	logl(long double);
 long		lrintl(long double);
 long		lroundl(long double);
 long double	modfl(long double, long double *); /* fundamentally !__pure2 */
@@ -429,53 +441,22 @@ long double	nextafterl(long double, long double);
 double		nexttoward(double, long double);
 float		nexttowardf(float, long double);
 long double	nexttowardl(long double, long double);
+long double	powl(long double, long double);
 long double	remainderl(long double, long double);
 long double	remquol(long double, long double, int *);
 long double	rintl(long double);
 long double	roundl(long double);
 long double	scalblnl(long double, long);
 long double	scalbnl(long double, int);
+long double	sinhl(long double);
 long double	sinl(long double);
 long double	sqrtl(long double);
+long double	tanhl(long double);
 long double	tanl(long double);
+long double	tgammal(long double);
 long double	truncl(long double);
 
 #endif /* __ISO_C_VISIBLE >= 1999 */
 __END_DECLS
 
 #endif /* !_MATH_H_ */
-
-/* separate header for cmath */
-#ifndef _MATH_EXTRA_H_
-#if __ISO_C_VISIBLE >= 1999
-#if _DECLARE_C99_LDBL_MATH
-
-#define _MATH_EXTRA_H_
-
-/*
- * extra long double versions of math functions for C99 and cmath
- */
-__BEGIN_DECLS
-
-long double	acoshl(long double);
-long double	asinhl(long double);
-long double	atanhl(long double);
-long double	coshl(long double);
-long double	erfcl(long double);
-long double	erfl(long double);
-long double	expm1l(long double);
-long double	lgammal(long double);
-long double	log10l(long double);
-long double	log1pl(long double);
-long double	log2l(long double);
-long double	logl(long double);
-long double	powl(long double, long double);
-long double	sinhl(long double);
-long double	tanhl(long double);
-long double	tgammal(long double);
-
-__END_DECLS
-
-#endif /* !_DECLARE_C99_LDBL_MATH */
-#endif /* __ISO_C_VISIBLE >= 1999 */
-#endif /* !_MATH_EXTRA_H_ */
diff --git a/tests/math_test.cpp b/tests/math_test.cpp
index 0b98e40f3..63ac71977 100644
--- a/tests/math_test.cpp
+++ b/tests/math_test.cpp
@@ -14,8 +14,6 @@
  * limitations under the License.
  */
 
-#define _DECLARE_C99_LDBL_MATH 1
-
 // This include (and the associated definition of __test_capture_signbit)
 // must be placed before any files that include <cmath> (gtest.h in this case).
 //