diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index d4c5978c..c934db88 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -58,7 +58,8 @@ if (PRJXRAY_BUILD_TESTING)
 		xilinx/xc7series/frame_address_test.cc
 		xilinx/xc7series/global_clock_region_test.cc
 		xilinx/xc7series/part_test.cc
-		xilinx/xc7series/row_test.cc)
+		xilinx/xc7series/row_test.cc
+		xilinx/xc7series/frames_test.cc)
 	target_link_libraries(xilinx_xc7series_test libprjxray gtest_main)
 	add_test(NAME xilinx_xc7series_test
 		 COMMAND xilinx_xc7series_test
diff --git a/lib/xilinx/xc7series/frames_test.cc b/lib/xilinx/xc7series/frames_test.cc
new file mode 100644
index 00000000..279c742d
--- /dev/null
+++ b/lib/xilinx/xc7series/frames_test.cc
@@ -0,0 +1,53 @@
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#include <prjxray/xilinx/xc7series/frames.h>
+#include <prjxray/xilinx/xc7series/part.h>
+
+namespace xc7series = prjxray::xilinx::xc7series;
+TEST(FramesTest, FillInMissingFrames) {
+	std::vector<xc7series::FrameAddress> test_part_addresses = {
+	    xc7series::FrameAddress(xc7series::BlockType::CLB_IO_CLK, false, 0,
+	                            0, 0),
+	    xc7series::FrameAddress(xc7series::BlockType::CLB_IO_CLK, false, 0,
+	                            0, 1),
+	    xc7series::FrameAddress(xc7series::BlockType::CLB_IO_CLK, false, 0,
+	                            0, 2),
+	    xc7series::FrameAddress(xc7series::BlockType::CLB_IO_CLK, false, 0,
+	                            0, 3),
+	    xc7series::FrameAddress(xc7series::BlockType::CLB_IO_CLK, false, 0,
+	                            0, 4)};
+
+	xc7series::Part test_part(0x1234, test_part_addresses);
+
+	xc7series::Frames frames;
+	frames.getFrames().emplace(std::make_pair(
+	    xc7series::FrameAddress(2), std::vector<uint32_t>(101, 0xCC)));
+	frames.getFrames().emplace(std::make_pair(
+	    xc7series::FrameAddress(3), std::vector<uint32_t>(101, 0xDD)));
+	frames.getFrames().emplace(std::make_pair(
+	    xc7series::FrameAddress(4), std::vector<uint32_t>(101, 0xEE)));
+
+	ASSERT_EQ(frames.getFrames().size(), 3);
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[2]),
+	          std::vector<uint32_t>(101, 0xCC));
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[3]),
+	          std::vector<uint32_t>(101, 0xDD));
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[4]),
+	          std::vector<uint32_t>(101, 0xEE));
+
+	frames.addMissingFrames(test_part);
+
+	ASSERT_EQ(frames.getFrames().size(), 5);
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[0]),
+	          std::vector<uint32_t>(101, 0));
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[1]),
+	          std::vector<uint32_t>(101, 0));
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[2]),
+	          std::vector<uint32_t>(101, 0xCC));
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[3]),
+	          std::vector<uint32_t>(101, 0xDD));
+	EXPECT_EQ(frames.getFrames().at(test_part_addresses[4]),
+	          std::vector<uint32_t>(101, 0xEE));
+}