diff --git a/src/Parser.php b/src/Parser.php
index a37511ab..6dae2180 100644
--- a/src/Parser.php
+++ b/src/Parser.php
@@ -34,6 +34,8 @@ public static function parse($entry)
      *
      * @param string $line
      *
+     * @throws \Dotenv\Exception\InvalidFileException
+     *
      * @return array
      */
     private static function splitStringIntoParts($line)
@@ -45,6 +47,12 @@ private static function splitStringIntoParts($line)
             list($name, $value) = array_map('trim', explode('=', $line, 2));
         }
 
+        if ($name === '') {
+            throw new InvalidFileException(
+                self::getErrorMessage('an unexpected equals', $line)
+            );
+        }
+
         return [$name, $value];
     }
 
@@ -53,15 +61,37 @@ private static function splitStringIntoParts($line)
      *
      * @param string $name
      *
+     * @throws \Dotenv\Exception\InvalidFileException
+     *
      * @return string
      */
     private static function sanitiseName($name)
     {
-        return trim(str_replace(['export ', '\'', '"'], '', $name));
+        $name = trim(str_replace(['export ', '\'', '"'], '', $name));
+
+        if (!self::isValidName($name)) {
+            throw new InvalidFileException(
+                self::getErrorMessage('an invalid name', $name)
+            );
+        }
+
+        return $name;
     }
 
     /**
-     * Strips quotes from the environment variable value.
+     * Is the given variable name valid?
+     *
+     * @param string $name
+     *
+     * @return bool
+     */
+    private static function isValidName($name)
+    {
+        return preg_match('~\A[a-zA-Z0-9_.]+\z~', $name) === 1;
+    }
+
+    /**
+     * Strips quotes and comments from the environment variable value.
      *
      * @param string|null $value
      *
@@ -75,46 +105,77 @@ private static function sanitiseValue($value)
             return $value;
         }
 
-        if (self::beginsWithAQuote($value)) { // value starts with a quote
-            $quote = $value[0];
-            $regexPattern = sprintf(
-                '/^
-                %1$s           # match a quote at the start of the value
-                (              # capturing sub-pattern used
-                 (?:           # we do not need to capture this
-                  [^%1$s\\\\]+ # any character other than a quote or backslash
-                  |\\\\\\\\    # or two backslashes together
-                  |\\\\%1$s    # or an escaped quote e.g \"
-                 )*            # as many characters that match the previous rules
-                )              # end of the capturing sub-pattern
-                %1$s           # and the closing quote
-                .*$            # and discard any string after the closing quote
-                /mx',
-                $quote
-            );
-            $value = preg_replace($regexPattern, '$1', $value);
-            $value = str_replace("\\$quote", $quote, $value);
-            $value = str_replace('\\\\', '\\', $value);
-        } else {
-            $parts = explode(' #', $value, 2);
-            $value = $parts[0];
-
-            // Unquoted values cannot contain whitespace
-            if (preg_match('/\s+/', $value) > 0) {
-                // Check if value is a comment (usually triggered when empty value with comment)
-                if (preg_match('/^#/', $value) > 0) {
-                    $value = '';
-                } else {
-                    throw new InvalidFileException(
-                        'Dotenv values containing spaces must be surrounded by quotes.'
-                    );
-                }
+        if (self::beginsWithAQuote($value)) {
+            return self::processQuotedValue($value);
+        }
+
+        // Strip comments from the left
+        $value = explode(' #', $value, 2)[0];
+
+        // Unquoted values cannot contain whitespace
+        if (preg_match('/\s+/', $value) > 0) {
+            // Check if value is a comment (usually triggered when empty value with comment)
+            if (preg_match('/^#/', $value) > 0) {
+                $value = '';
+            } else {
+                throw new InvalidFileException(
+                    self::getErrorMessage('an unexpected space', $value)
+                );
             }
         }
 
         return $value;
     }
 
+    /**
+     * Strips quotes from the environment variable value.
+     *
+     * @param string $value
+     *
+     * @return string
+     */
+    private static function processQuotedValue($value)
+    {
+        $quote = $value[0];
+
+        $pattern = sprintf(
+            '/^
+            %1$s           # match a quote at the start of the value
+            (              # capturing sub-pattern used
+             (?:           # we do not need to capture this
+              [^%1$s\\\\]+ # any character other than a quote or backslash
+              |\\\\\\\\    # or two backslashes together
+              |\\\\%1$s    # or an escaped quote e.g \"
+             )*            # as many characters that match the previous rules
+            )              # end of the capturing sub-pattern
+            %1$s           # and the closing quote
+            .*$            # and discard any string after the closing quote
+            /mx',
+            $quote
+        );
+
+        $value = preg_replace($pattern, '$1', $value);
+
+        return str_replace('\\\\', '\\', str_replace("\\$quote", $quote, $value));
+    }
+
+    /**
+     * Generate a friendly error message.
+     *
+     * @param string $cause
+     * @param string $subject
+     *
+     * @return string
+     */
+    private static function getErrorMessage($cause, $subject)
+    {
+        return sprintf(
+            'Failed to parse dotenv file due to %s. Failed at [%s].',
+            $cause,
+            strtok($subject, "\n")
+        );
+    }
+
     /**
      * Determine if the given string begins with a quote.
      *
diff --git a/tests/Dotenv/DotenvTest.php b/tests/Dotenv/DotenvTest.php
index 1a5b816e..7863af42 100644
--- a/tests/Dotenv/DotenvTest.php
+++ b/tests/Dotenv/DotenvTest.php
@@ -86,16 +86,6 @@ public function testQuotedDotenvLoadsEnvironmentVars()
         $this->assertSame('test some escaped characters like a quote (") or maybe a backslash (\\)', getenv('QESCAPED'));
     }
 
-    /**
-     * @expectedException \Dotenv\Exception\InvalidFileException
-     * @expectedExceptionMessage Dotenv values containing spaces must be surrounded by quotes.
-     */
-    public function testSpacedValuesWithoutQuotesThrowsException()
-    {
-        $dotenv = Dotenv::create(dirname(__DIR__).'/fixtures/env-wrong', 'spaced-wrong.env');
-        $dotenv->load();
-    }
-
     public function testExportedDotenvLoadsEnvironmentVars()
     {
         $dotenv = Dotenv::create($this->fixturesFolder, 'exported.env');
diff --git a/tests/Dotenv/ParserTest.php b/tests/Dotenv/ParserTest.php
index f5081633..dba2392b 100644
--- a/tests/Dotenv/ParserTest.php
+++ b/tests/Dotenv/ParserTest.php
@@ -19,4 +19,31 @@ public function testExportParse()
     {
         $this->assertSame(['FOO', 'bar baz'], Parser::parse('export FOO="bar baz"'));
     }
+
+    /**
+     * @expectedException \Dotenv\Exception\InvalidFileException
+     * @expectedExceptionMessage Failed to parse dotenv file due to an unexpected space. Failed at [bar baz].
+     */
+    public function testParseInvalidSpaces()
+    {
+        Parser::parse('FOO=bar baz');
+    }
+
+    /**
+     * @expectedException \Dotenv\Exception\InvalidFileException
+     * @expectedExceptionMessage Failed to parse dotenv file due to an unexpected equals. Failed at [=].
+     */
+    public function testParseStrayEquals()
+    {
+        Parser::parse('=');
+    }
+
+    /**
+     * @expectedException \Dotenv\Exception\InvalidFileException
+     * @expectedExceptionMessage Failed to parse dotenv file due to an invalid name. Failed at [FOO_ASD!].
+     */
+    public function testParseInvalidName()
+    {
+        Parser::parse('FOO_ASD!=BAZ');
+    }
 }
diff --git a/tests/fixtures/env-wrong/spaced-wrong.env b/tests/fixtures/env-wrong/spaced-wrong.env
deleted file mode 100644
index 5e63f27e..00000000
--- a/tests/fixtures/env-wrong/spaced-wrong.env
+++ /dev/null
@@ -1 +0,0 @@
-QWFOO=with spaces