1 files changed, 3 insertions, 1 deletions
diff --git a/src/PJ_lagrng.c b/src/PJ_lagrng.c
index cf6d97d6..d2b53b09 100644
--- a/src/PJ_lagrng.c
+++ b/src/PJ_lagrng.c
@@ -1,5 +1,8 @@
 #define PJ_LIB__
+
 #include <errno.h>
+#include <math.h>
+
 #include "proj.h"
 #include "projects.h"
 
@@ -60,4 +63,3 @@ PJ *PROJECTION(lagrng) {
 
     return P;
 }
-