diff --git a/core/src/main/java/hudson/FilePath.java b/core/src/main/java/hudson/FilePath.java
index 6f897dad6e..719b01db93 100644
--- a/core/src/main/java/hudson/FilePath.java
+++ b/core/src/main/java/hudson/FilePath.java
@@ -158,6 +158,8 @@ public final class FilePath implements Serializable {
      * Checks if the remote path is Unix.
      */
     private boolean isUnix() {
+        // Windows absolute path always include ':', but this is not a valid char in Unix file systems.
+        if(remote.contains(":"))    return false;
         // Windows can handle '/' as a path separator but Unix can't,
         // so err on Unix side
         return remote.indexOf("\\")==-1;
diff --git a/core/src/main/java/hudson/model/Slave.java b/core/src/main/java/hudson/model/Slave.java
index 8169ba4720..a98ecc16c0 100644
--- a/core/src/main/java/hudson/model/Slave.java
+++ b/core/src/main/java/hudson/model/Slave.java
@@ -527,9 +527,10 @@ public final class Slave implements Node, Serializable {
     }
 
     public Launcher createLauncher(TaskListener listener) {
+        // Windows absolute path always include ':', but this is not a valid char in Unix file systems.
         // Windows can handle '/' as a path separator but Unix can't,
         // so err on Unix side
-        boolean isUnix = remoteFS.indexOf("\\") == -1;
+        boolean isUnix = !remoteFS.contains(":") && !remoteFS.contains("\\");
 
         return new RemoteLauncher(listener, getComputer().getChannel(),isUnix);
     }