diff --git a/packages/imports/package.json b/packages/imports/package.json
index 1ba834d..9b28a46 100644
--- a/packages/imports/package.json
+++ b/packages/imports/package.json
@@ -18,6 +18,7 @@
     "debug": "^3.1.0",
     "hosted-git-info": "^2.6.0",
     "path-browserify": "^1.0.0",
-    "url": "^0.11.0"
+    "url": "^0.11.0",
+    "is-url": "^1.2.4"
   }
 }
diff --git a/packages/imports/src/utils.ts b/packages/imports/src/utils.ts
index c1d810d..8dbb679 100644
--- a/packages/imports/src/utils.ts
+++ b/packages/imports/src/utils.ts
@@ -1,4 +1,5 @@
 import { ResolverEngine } from "@resolver-engine/core";
+import isUrl from "is-url";
 import pathSys from "path";
 import urlSys from "url";
 import { ImportFile } from "./parsers/importparser";
@@ -25,6 +26,25 @@ export function findImports(data: ImportFile): string[] {
   return result;
 }
 
+function resolvePath(workingDir: string, relativePath: string): string {
+  // If the working dir is an URL (a file imported from an URL location)
+  // or the relative path is an URL (an URL imported from a local file)
+  // use url.resolve, which will work in both cases.
+  // > url.resolve('/local/folder/', 'http://example.com/myfile.sol')
+  // 'http://example.com/myfile.sol'
+  // > url.resolve('http://example.com/', 'myfile.sol')
+  // 'http://example.com/myfile.sol'
+  //
+  // If not, use path.resolve, since using url.resolve will escape certain
+  // charaters (e.g. a space as an %20), breaking the path
+  // > url.resolve('/local/path/with spaces/', 'myfile.sol')
+  // '/local/path/with%20spaces/myfile.sol'
+
+  return isUrl(workingDir) || isUrl(relativePath)
+    ? urlSys.resolve(workingDir, relativePath)
+    : pathSys.resolve(pathSys.dirname(workingDir), relativePath);
+}
+
 interface ImportTreeNode extends ImportFile {
   uri: string;
   // uri and url the same as in rest of resolver-engine
@@ -105,7 +125,7 @@ export async function gatherSources(
   if (workingDir !== "") {
     workingDir += "/";
   }
-  const absoluteRoots = roots.map(what => urlSys.resolve(workingDir, what));
+  const absoluteRoots = roots.map(what => resolvePath(workingDir, what));
   for (const absWhat of absoluteRoots) {
     queue.push({ cwd: workingDir, file: absWhat, relativeTo: workingDir });
     alreadyImported.add(absWhat);
@@ -120,7 +140,7 @@ export async function gatherSources(
     // if not - return the same name it was imported with
     let relativePath: string;
     if (fileData.file[0] === ".") {
-      relativePath = urlSys.resolve(fileData.relativeTo, fileData.file);
+      relativePath = resolvePath(fileData.relativeTo, fileData.file);
       result.push({ url: relativePath, source: resolvedFile.source, provider: resolvedFile.provider });
     } else {
       relativePath = fileData.file;
@@ -131,7 +151,7 @@ export async function gatherSources(
     for (const foundImport of foundImports) {
       let importName: string;
       if (foundImport[0] === ".") {
-        importName = urlSys.resolve(relativePath, foundImport);
+        importName = resolvePath(relativePath, foundImport);
       } else {
         importName = foundImport;
       }