diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
@@ -772,7 +772,8 @@
 
   // check whether we have a windows path, and so the first character is a
   // drive-letter not a hostname.
-  if (host.size() == 1 && llvm::isAlpha(host[0]) && path.startswith("\\"))
+  if (host.size() == 1 && llvm::isAlpha(host[0]) &&
+      (path.startswith("\\") || path.startswith("/")))
     return path_from_dwarf;
 
   return path;
diff --git a/lldb/source/Utility/FileSpec.cpp b/lldb/source/Utility/FileSpec.cpp
--- a/lldb/source/Utility/FileSpec.cpp
+++ b/lldb/source/Utility/FileSpec.cpp
@@ -311,7 +311,8 @@
   if (absolute_path.startswith(R"(\\)"))
     return Style::windows;
   if (absolute_path.size() >= 3 && llvm::isAlpha(absolute_path[0]) &&
-      absolute_path.substr(1, 2) == R"(:\)")
+      (absolute_path.substr(1, 2) == R"(:\)" ||
+       absolute_path.substr(1, 2) == R"(:/)"))
     return Style::windows;
   return llvm::None;
 }
diff --git a/lldb/unittests/Utility/FileSpecTest.cpp b/lldb/unittests/Utility/FileSpecTest.cpp
--- a/lldb/unittests/Utility/FileSpecTest.cpp
+++ b/lldb/unittests/Utility/FileSpecTest.cpp
@@ -196,9 +196,12 @@
   EXPECT_EQ(FileSpec::Style::posix, FileSpec::GuessPathStyle("//net/bar.txt"));
   EXPECT_EQ(FileSpec::Style::windows,
             FileSpec::GuessPathStyle(R"(C:\foo.txt)"));
+  EXPECT_EQ(FileSpec::Style::windows,
+            FileSpec::GuessPathStyle(R"(C:/foo.txt)"));
   EXPECT_EQ(FileSpec::Style::windows,
             FileSpec::GuessPathStyle(R"(\\net\foo.txt)"));
   EXPECT_EQ(FileSpec::Style::windows, FileSpec::GuessPathStyle(R"(Z:\)"));
+  EXPECT_EQ(FileSpec::Style::windows, FileSpec::GuessPathStyle(R"(Z:/)"));
   EXPECT_EQ(llvm::None, FileSpec::GuessPathStyle("foo.txt"));
   EXPECT_EQ(llvm::None, FileSpec::GuessPathStyle("foo/bar.txt"));
   EXPECT_EQ(llvm::None, FileSpec::GuessPathStyle("Z:"));