Remove trailing / from avifincrtest arg

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d7a7214..77aac79 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -77,7 +77,7 @@
 
     add_executable(avifincrtest gtest/avifincrtest.cc)
     target_link_libraries(avifincrtest aviftest_helpers avifincrtest_helpers)
-    add_test(NAME avifincrtest COMMAND avifincrtest ${CMAKE_CURRENT_SOURCE_DIR}/data/)
+    add_test(NAME avifincrtest COMMAND avifincrtest ${CMAKE_CURRENT_SOURCE_DIR}/data)
 
     add_executable(avifmetadatatest gtest/avifmetadatatest.cc)
     target_link_libraries(avifmetadatatest aviftest_helpers ${GTEST_BOTH_LIBRARIES})
diff --git a/tests/gtest/avifincrtest.cc b/tests/gtest/avifincrtest.cc
index d55c7d0..686ffd6 100644
--- a/tests/gtest/avifincrtest.cc
+++ b/tests/gtest/avifincrtest.cc
@@ -25,7 +25,7 @@
 
 // Reads the file with file_name into bytes and returns them.
 testutil::AvifRwData ReadFile(const char* file_name) {
-  std::ifstream file(std::string(data_path) + file_name,
+  std::ifstream file(std::string(data_path) + "/" + file_name,
                      std::ios::binary | std::ios::ate);
   testutil::AvifRwData bytes;
   avifRWDataRealloc(&bytes,