1 files changed, 3 insertions, 1 deletions
diff --git a/src/PJ_omerc.c b/src/PJ_omerc.c
index 32bf5c14..70c12e27 100644
--- a/src/PJ_omerc.c
+++ b/src/PJ_omerc.c
@@ -22,7 +22,10 @@
 ** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 #define PJ_LIB__
+
 #include <errno.h>
+#include <math.h>
+
 #include "proj.h"
 #include "projects.h"
 
@@ -222,4 +225,3 @@ PJ *PROJECTION(omerc) {
 
     return P;
 }
-