diff --git a/.gitmodules b/.gitmodules
index 3e1e3f1d..e40bb869 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -15,7 +15,7 @@
 	url = https://github.com/jbeder/yaml-cpp.git
 [submodule "third_party/fasm"]
 	path = third_party/fasm
-	url = https://github.com/SymbiFlow/fasm.git
+	url = https://github.com/openxc7/fasm.git
 [submodule "third_party/python-sdf-timing"]
 	path = third_party/python-sdf-timing
 	url = https://github.com/SymbiFlow/python-sdf-timing.git
diff --git a/lib/include/prjxray/memory_mapped_file.h b/lib/include/prjxray/memory_mapped_file.h
index 6aeb8210..81f8dd72 100644
--- a/lib/include/prjxray/memory_mapped_file.h
+++ b/lib/include/prjxray/memory_mapped_file.h
@@ -12,6 +12,7 @@
 
 #include <memory>
 #include <string>
+#include <cstdint>
 
 #include <absl/types/span.h>
 
diff --git a/third_party/fasm b/third_party/fasm
index ffafe821..2f57ccb1 160000
--- a/third_party/fasm
+++ b/third_party/fasm
@@ -1 +1 @@
-Subproject commit ffafe821bae68637fe46e36bcfd2a01b97cdf6f2
+Subproject commit 2f57ccb1727a120e8cacbb95c578f3c71bdcc95a
diff --git a/third_party/gflags b/third_party/gflags
index 03a4842c..33bb3461 160000
--- a/third_party/gflags
+++ b/third_party/gflags
@@ -1 +1 @@
-Subproject commit 03a4842c9c6aaef438d7bf0c84e8a62c8064992b
+Subproject commit 33bb3461e10864b5406353d3a1fb7ff34c2314b8
diff --git a/tools/bitread.cc b/tools/bitread.cc
index 796b8c75..35ec139a 100644
--- a/tools/bitread.cc
+++ b/tools/bitread.cc
@@ -67,9 +67,9 @@ uint32_t frame_range_begin = 0, frame_range_end = 0;
 std::vector<uint32_t> zero_frame(101);
 
 struct BitReader {
-	BitReader(const std::vector<uint8_t>& bytes) : bytes_(bytes) {}
+	BitReader(const absl::Span<uint8_t>& bytes) : bytes_(bytes) {}
 
-	const std::vector<uint8_t>& bytes_;
+	const absl::Span<uint8_t>& bytes_;
 
 	template <typename T>
 	int operator()(T& arg) {
@@ -319,7 +319,7 @@ int main(int argc, char** argv) {
 		frame_range_end = strtol(p.second.c_str(), nullptr, 0) + 1;
 	}
 
-	std::vector<uint8_t> in_bytes;
+	absl::Span<uint8_t> in_bytes;
 	if (argc == 2) {
 		auto in_file_name = argv[1];
 		auto in_file =
@@ -333,16 +333,18 @@ int main(int argc, char** argv) {
 		std::cout << "Bitstream size: " << in_file->size() << " bytes"
 		          << std::endl;
 
-		in_bytes = std::vector<uint8_t>(
-		    static_cast<uint8_t*>(in_file->data()),
-		    static_cast<uint8_t*>(in_file->data()) + in_file->size());
+		in_bytes = absl::Span<uint8_t>(
+		    static_cast<uint8_t*>(in_file->data()), in_file->size());
 	} else {
+		std::vector<uint8_t> t;
 		while (1) {
 			int c = getchar();
 			if (c == EOF)
 				break;
-			in_bytes.push_back(c);
+			t.push_back(c);
 		}
+		in_bytes = absl::Span<uint8_t>(
+			static_cast<uint8_t*>(t.data()), t.size());
 
 		std::cout << "Bitstream size: " << in_bytes.size() << " bytes"
 		          << std::endl;