diff --git a/src/OSspecific/MSwindows/MSwindows.C b/src/OSspecific/MSwindows/MSwindows.C
index 9ea78be680..3be89545c1 100644
--- a/src/OSspecific/MSwindows/MSwindows.C
+++ b/src/OSspecific/MSwindows/MSwindows.C
@@ -1197,11 +1197,23 @@ void* Foam::dlOpen(const fileName& libName, const bool check)
 
     void* handle = ::LoadLibrary(libso.c_str());
 
-    if (!handle && !libso.startsWith("lib"))
+    if
+    (
+        !handle
+     && libName.find('/') == std::string::npos
+     && !libso.startsWith("lib")
+    )
     {
         // Try with 'lib' prefix
         libso = "lib" + libso;
         handle = ::LoadLibrary(libso.c_str());
+
+        if (MSwindows::debug)
+        {
+            std::cout
+                << "dlOpen(const fileName&)"
+                << " : dlopen of " << libso << std::endl;
+        }
     }
 
     if (handle)
diff --git a/src/OSspecific/POSIX/POSIX.C b/src/OSspecific/POSIX/POSIX.C
index 4b970b4a06..35568ced49 100644
--- a/src/OSspecific/POSIX/POSIX.C
+++ b/src/OSspecific/POSIX/POSIX.C
@@ -1670,11 +1670,22 @@ void* Foam::dlOpen(const fileName& libName, const bool check)
     {
         fileName libso;
 
-        if (!libName.startsWith("lib"))
+        if
+        (
+            libName.find('/') == std::string::npos
+         && !libName.startsWith("lib")
+        )
         {
             // Try with 'lib' prefix
             libso = "lib" + libName;
             handle = ::dlopen(libso.c_str(), ldflags);
+
+            if (POSIX::debug)
+            {
+                std::cout
+                    << "dlOpen(const fileName&)"
+                    << " : dlopen of " << libso << std::endl;
+            }
         }
         else
         {
@@ -1687,6 +1698,13 @@ void* Foam::dlOpen(const fileName& libName, const bool check)
         {
             libso = libso.lessExt().ext(EXT_SO);
             handle = ::dlopen(libso.c_str(), ldflags);
+
+            if (POSIX::debug)
+            {
+                std::cout
+                    << "dlOpen(const fileName&)"
+                    << " : dlopen of " << libso << std::endl;
+            }
         }
     }