diff --git a/wdl-engine/tests/tasks.rs b/wdl-engine/tests/tasks.rs
index 465dd582c..353e83826 100644
--- a/wdl-engine/tests/tasks.rs
+++ b/wdl-engine/tests/tasks.rs
@@ -22,7 +22,6 @@ use std::collections::HashSet;
 use std::env;
 use std::ffi::OsStr;
 use std::fs;
-use std::path::MAIN_SEPARATOR;
 use std::path::Path;
 use std::path::PathBuf;
 use std::path::absolute;
@@ -88,19 +87,23 @@ fn find_tests() -> Vec<PathBuf> {
 
 /// Normalizes a result.
 fn normalize(root: &Path, s: &str) -> String {
+    // Normalize paths separation characters first
+    let s = s
+        .replace("\\", "/")
+        .replace("//", "/")
+        .replace("\r\n", "\n");
+
     // Strip any paths that start with the root directory
-    let s: Cow<'_, str> = if let Some(mut root) = root.to_str().map(str::to_string) {
-        if !root.ends_with(MAIN_SEPARATOR) {
-            root.push(MAIN_SEPARATOR);
+    if let Some(root) = root.to_str().map(str::to_string) {
+        let mut root = root.replace('\\', "/");
+        if !root.ends_with('/') {
+            root.push('/');
         }
 
-        s.replace(&root, "").into()
+        s.replace(&root, "")
     } else {
-        s.into()
-    };
-
-    // Normalize paths separation characters
-    s.replace('\\', "/").replace("\r\n", "\n")
+        s
+    }
 }
 
 /// Compares a single result.
diff --git a/wdl-engine/tests/tasks/flags-task/source.wdl b/wdl-engine/tests/tasks/flags-task/source.wdl
index 94a7e579a..98e971d32 100644
--- a/wdl-engine/tests/tasks/flags-task/source.wdl
+++ b/wdl-engine/tests/tasks/flags-task/source.wdl
@@ -15,7 +15,7 @@ task flags {
 
     # Instead, make both the flag and the value conditional on `max_matches`
     # being defined.
-    grep ~{"-m " + max_matches} ~{pattern} ~{infile} | wc -l | sed 's/^ *//'
+    grep ~{"-m " + max_matches} ~{pattern} '~{infile}' | wc -l | sed 's/^ *//'
   >>>
 
   output {
diff --git a/wdl-engine/tests/tasks/input-type-qualifiers/source.wdl b/wdl-engine/tests/tasks/input-type-qualifiers/source.wdl
index cabeb5681..6f7147ca8 100644
--- a/wdl-engine/tests/tasks/input-type-qualifiers/source.wdl
+++ b/wdl-engine/tests/tasks/input-type-qualifiers/source.wdl
@@ -13,13 +13,13 @@ task input_type_quantifiers {
   }
 
   command <<<
-    cat ~{write_lines(a)} >> result
-    cat ~{write_lines(b)} >> result
+    cat '~{write_lines(a)}' >> result
+    cat '~{write_lines(b)}' >> result
     ~{if defined(c) then 
-    "cat ~{write_lines(select_first([c]))} >> result"
+    "cat '~{write_lines(select_first([c]))}' >> result"
     else ""}
     ~{if defined(e) then 
-    "cat ~{write_lines(select_first([e]))} >> result"
+    "cat '~{write_lines(select_first([e]))}' >> result"
     else ""}
   >>>
 
diff --git a/wdl-engine/tests/tasks/multiline-strings2/outputs.json b/wdl-engine/tests/tasks/multiline-strings2/outputs.json
index 03dc2eb9c..905587c9c 100644
--- a/wdl-engine/tests/tasks/multiline-strings2/outputs.json
+++ b/wdl-engine/tests/tasks/multiline-strings2/outputs.json
@@ -6,5 +6,5 @@
   "multiline_strings2.hw4": "hello  world",
   "multiline_strings2.hw5": "hello  world",
   "multiline_strings2.hw6": "hello  world",
-  "multiline_strings2.not_equivalent": "hello ///n  world"
+  "multiline_strings2.not_equivalent": "hello //n  world"
 }
\ No newline at end of file
diff --git a/wdl-engine/tests/tasks/private-declaration-task/source.wdl b/wdl-engine/tests/tasks/private-declaration-task/source.wdl
index 1bcd2a705..2e7786aa8 100644
--- a/wdl-engine/tests/tasks/private-declaration-task/source.wdl
+++ b/wdl-engine/tests/tasks/private-declaration-task/source.wdl
@@ -9,7 +9,7 @@ task private_declaration {
   Int num_lines_clamped = if num_lines > 3 then 3 else num_lines
 
   command <<<
-  head -~{num_lines_clamped} ~{write_lines(lines)}
+  head -~{num_lines_clamped} '~{write_lines(lines)}'
   >>>
 
   output {