diff --git a/src/internal/libm.h b/src/internal/libm.h
index 946c310d70e5d163983d92adfb5e5ecb6e6484fc..9f0d3bc834ef615c9fd4f39155c2ad86805e80d5 100644
--- a/src/internal/libm.h
+++ b/src/internal/libm.h
@@ -19,8 +19,6 @@
 #include <complex.h>
 #include <endian.h>
 
-#include "libc.h"
-
 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
 #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __LITTLE_ENDIAN
 union ldshape {
diff --git a/src/math/lgamma_r.c b/src/math/lgamma_r.c
index e3ed1733037bf40bfdf80ea2f0af007a11278ff9..82e296f58ed7c059c1893f9b613558a581c82bee 100644
--- a/src/math/lgamma_r.c
+++ b/src/math/lgamma_r.c
@@ -79,6 +79,7 @@
  */
 
 #include "libm.h"
+#include "libc.h"
 
 static const double
 two52= 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
diff --git a/src/math/lgammaf_r.c b/src/math/lgammaf_r.c
index 976986aa4aa13e2ec8d1f712787594e02b231457..dc65bace3247a39562f92923840882dba1f8729b 100644
--- a/src/math/lgammaf_r.c
+++ b/src/math/lgammaf_r.c
@@ -14,6 +14,7 @@
  */
 
 #include "libm.h"
+#include "libc.h"
 
 static const float
 two23= 8.3886080000e+06, /* 0x4b000000 */
diff --git a/src/math/lgammal.c b/src/math/lgammal.c
index 5d56358e22cc0a0cab18372d43aa88cb940cdd66..cc4895ebb8a3b94e1cd5fe12ea2c625af9fcc5a8 100644
--- a/src/math/lgammal.c
+++ b/src/math/lgammal.c
@@ -87,6 +87,7 @@
 
 #define _GNU_SOURCE
 #include "libm.h"
+#include "libc.h"
 
 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
 double __lgamma_r(double x, int *sg);
diff --git a/src/math/signgam.c b/src/math/signgam.c
index b39ceb046898f31843f08606e052f0052b76a85e..cd728001ba375c46f660791d5c6a5cc7edab8085 100644
--- a/src/math/signgam.c
+++ b/src/math/signgam.c
@@ -1,4 +1,5 @@
-#include "libm.h"
+#include <math.h>
+#include "libc.h"
 
 int __signgam = 0;