diff --git a/frontends/ilang/lexer.l b/frontends/ilang/lexer.l
index 292321e88..9669f0924 100644
--- a/frontends/ilang/lexer.l
+++ b/frontends/ilang/lexer.l
@@ -35,7 +35,7 @@
 USING_YOSYS_NAMESPACE
 
 #define YY_INPUT(buf,result,max_size) \
-        result = ILANG_FRONTEND::lexin->readsome(buf, max_size);
+        result = readsome(*ILANG_FRONTEND::lexin, buf, max_size);
 
 %}
 
diff --git a/frontends/verilog/lexer.l b/frontends/verilog/lexer.l
index c9302aba8..98f360885 100644
--- a/frontends/verilog/lexer.l
+++ b/frontends/verilog/lexer.l
@@ -64,7 +64,7 @@ YOSYS_NAMESPACE_END
 	return TOK_ID;
 
 #define YY_INPUT(buf,result,max_size) \
-	result = lexin->readsome(buf, max_size);
+	result = readsome(*lexin, buf, max_size);
 
 %}
 
diff --git a/frontends/verilog/preproc.cc b/frontends/verilog/preproc.cc
index 7e14fcb84..b4e77c31b 100644
--- a/frontends/verilog/preproc.cc
+++ b/frontends/verilog/preproc.cc
@@ -202,7 +202,7 @@ static void input_file(std::istream &f, std::string filename)
 	auto it = input_buffer.begin();
 
 	input_buffer.insert(it, "`file_push " + filename + "\n");
-	while ((rc = f.readsome(buffer, sizeof(buffer)-1)) > 0) {
+	while ((rc = readsome(f, buffer, sizeof(buffer)-1)) > 0) {
 		buffer[rc] = 0;
 		input_buffer.insert(it, buffer);
 	}
diff --git a/kernel/yosys.cc b/kernel/yosys.cc
index 921f2b383..a40ad4372 100644
--- a/kernel/yosys.cc
+++ b/kernel/yosys.cc
@@ -166,6 +166,22 @@ bool patmatch(const char *pattern, const char *string)
 	return false;
 }
 
+int readsome(std::istream &f, char *s, int n)
+{
+	int rc = f.readsome(s, n);
+
+	// win32 sometimes returns 0 on a non-empty stream..
+	if (rc == 0) {
+		int c = f.get();
+		if (c != EOF) {
+			*s = c;
+			rc = 1;
+		}
+	}
+
+	return rc;
+}
+
 int GetSize(RTLIL::Wire *wire)
 {
 	return wire->width;
diff --git a/kernel/yosys.h b/kernel/yosys.h
index 919e3bb98..d38e60ceb 100644
--- a/kernel/yosys.h
+++ b/kernel/yosys.h
@@ -86,6 +86,7 @@ std::string stringf(const char *fmt, ...) __attribute__ ((format (printf, 1, 2))
 std::string vstringf(const char *fmt, va_list ap);
 std::string next_token(std::string &text, const char *sep);
 bool patmatch(const char *pattern, const char *string);
+int readsome(std::istream &f, char *s, int n);
 
 template<typename T> int GetSize(const T &obj) { return obj.size(); }
 int GetSize(RTLIL::Wire *wire);
diff --git a/passes/cmds/write_file.cc b/passes/cmds/write_file.cc
index 9f22861a5..3f4419724 100644
--- a/passes/cmds/write_file.cc
+++ b/passes/cmds/write_file.cc
@@ -70,7 +70,7 @@ struct WriteFileFrontend : public Frontend {
 		char buffer[64 * 1024];
 		size_t bytes;
 
-		while (0 < (bytes = f->readsome(buffer, sizeof(buffer))))
+		while (0 < (bytes = readsome(*f, buffer, sizeof(buffer))))
 			fwrite(buffer, bytes, 1, of);
 
 		fclose(of);