diff --git a/src/TabulatedPotential.cu b/src/TabulatedPotential.cu
index b4548ed91dfc1769da31dcb56915adb0f96e9e60..bac84720359ff8ce3555b147c73480cf4032ae77 100644
--- a/src/TabulatedPotential.cu
+++ b/src/TabulatedPotential.cu
@@ -97,6 +97,10 @@ TabulatedPotential::~TabulatedPotential() {
 
 int TabulatedPotential::countValueLines(const char* fileName) {
 	FILE* inp = fopen(fileName, "r");
+	if (inp == NULL) {
+		printf("TabulatedPotential::countValueLines Could not open file '%s'\n", fileName);
+		exit(-1);
+	}
 	char line[256];
 	int count = 0;