1 files changed, 3 insertions, 1 deletions
diff --git a/src/PJ_putp4p.c b/src/PJ_putp4p.c
index 958f9681..b716060a 100644
--- a/src/PJ_putp4p.c
+++ b/src/PJ_putp4p.c
@@ -1,5 +1,8 @@
 #define PJ_LIB__
+
 #include <errno.h>
+#include <math.h>
+
 #include "projects.h"
 
 struct pj_opaque {
@@ -69,4 +72,3 @@ PJ *PROJECTION(weren) {
 
     return P;
 }
-