diff --git a/pkg/solver/parallel.go b/pkg/solver/parallel.go
index 47a886c7..27f994f3 100644
--- a/pkg/solver/parallel.go
+++ b/pkg/solver/parallel.go
@@ -100,7 +100,7 @@ func (s *Parallel) buildParallelFormula(formulas []bf.Formula, packages pkg.Pack
 	go func() {
 		for t := range results {
 			formulas = append(formulas, t)
-			wg.Done() // ** move the `Done()` call here
+			wg.Done()
 		}
 	}()
 
@@ -139,19 +139,45 @@ func (s *Parallel) BuildWorld(includeInstalled bool) (bf.Formula, error) {
 func (s *Parallel) getList(db pkg.PackageDatabase, lsp pkg.Packages) (pkg.Packages, error) {
 	var ls pkg.Packages
 
-	for _, pp := range lsp {
-		cp, err := db.FindPackage(pp)
-		if err != nil {
-			packages, err := pp.Expand(db)
-			// Expand, and relax search - if not found pick the same one
-			if err != nil || len(packages) == 0 {
-				cp = pp
-			} else {
-				cp = packages.Best(nil)
+	var wg = new(sync.WaitGroup)
+	all := make(chan pkg.Package)
+	results := make(chan pkg.Package, 1)
+	for i := 0; i < s.Concurrency; i++ {
+		wg.Add(1)
+		go func(wg *sync.WaitGroup, c <-chan pkg.Package) {
+			//defer wg.Done()
+			for p := range c {
+				cp, err := db.FindPackage(p)
+				if err != nil {
+					packages, err := p.Expand(db)
+					// Expand, and relax search - if not found pick the same one
+					if err != nil || len(packages) == 0 {
+						cp = p
+					} else {
+						cp = packages.Best(nil)
+					}
+				}
+				ls = append(ls, cp)
+				results <- cp
+
 			}
-		}
-		ls = append(ls, cp)
+		}(wg, all)
 	}
+
+	go func() {
+		for t := range results {
+			ls = append(ls, t)
+			wg.Done()
+		}
+	}()
+
+	for _, pp := range lsp {
+		all <- pp
+	}
+
+	close(all)
+	wg.Wait()
+
 	return ls, nil
 }
 
@@ -196,8 +222,6 @@ func (s *Parallel) ConflictsWith(pack pkg.Package, lsp pkg.Packages) (bool, erro
 	p, err := s.DefinitionDatabase.FindPackage(pack)
 	if err != nil {
 		p = pack //Relax search, otherwise we cannot compute solutions for packages not in definitions
-
-		//	return false, errors.Wrap(err, "Package not found in definition db")
 	}
 
 	ls, err := s.getList(s.DefinitionDatabase, lsp)
@@ -223,23 +247,50 @@ func (s *Parallel) ConflictsWith(pack pkg.Package, lsp pkg.Packages) (bool, erro
 	}
 	formulas = append(formulas, bf.And(bf.Not(P), r))
 
-	for _, i := range ls {
-		if i.Matches(p) {
-			continue
-		}
-		// XXX: Skip check on any of its requires ?  ( Drop to avoid removing system packages when selecting an uninstall)
-		// if i.RequiresContains(p) {
-		// 	fmt.Println("Requires found")
-		// 	continue
-		// }
+	var wg = new(sync.WaitGroup)
 
-		encodedI, err := i.Encode(s.ParallelDatabase)
-		if err != nil {
-			return false, err
-		}
-		I := bf.Var(encodedI)
-		formulas = append(formulas, bf.And(I, r))
+	all := make(chan pkg.Package)
+	results := make(chan bf.Formula, 1)
+	for i := 0; i < s.Concurrency; i++ {
+		wg.Add(1)
+		go func(wg *sync.WaitGroup, c <-chan pkg.Package) {
+			//defer wg.Done()
+			for i := range c {
+				if i.Matches(p) {
+					continue
+				}
+
+				// XXX: Skip check on any of its requires ?  ( Drop to avoid removing system packages when selecting an uninstall)
+				// if i.RequiresContains(p) {
+				// 	fmt.Println("Requires found")
+				// 	continue
+				// }
+
+				encodedI, err := i.Encode(s.ParallelDatabase)
+				if err != nil {
+					panic(err)
+				}
+				I := bf.Var(encodedI)
+
+				results <- bf.And(I, r)
+			}
+		}(wg, all)
 	}
+
+	go func() {
+		for t := range results {
+			formulas = append(formulas, t)
+			wg.Done()
+		}
+	}()
+
+	for _, p := range ls {
+		all <- p
+	}
+
+	close(all)
+	wg.Wait()
+
 	model := bf.Solve(bf.And(formulas...))
 	if model == nil {
 		return true, nil
@@ -328,24 +379,47 @@ func (s *Parallel) UpgradeUniverse(dropremoved bool) (pkg.Packages, PackagesAsse
 		universe.CreatePackage(p)
 	}
 
+	var wg = new(sync.WaitGroup)
+	all := make(chan pkg.Package)
+	results := make(chan []pkg.Package, 1)
+	for i := 0; i < s.Concurrency; i++ {
+		wg.Add(1)
+		go func(wg *sync.WaitGroup, c <-chan pkg.Package) {
+			//defer wg.Done()
+			for p := range c {
+				available, err := universe.FindPackageVersions(p)
+				if err != nil {
+					removed = append(removed, p)
+				}
+				if len(available) == 0 {
+					continue
+				}
+
+				bestmatch := available.Best(nil)
+				// Found a better version available
+				if !bestmatch.Matches(p) {
+					results <- []pkg.Package{p, bestmatch}
+				}
+			}
+		}(wg, all)
+	}
+
+	go func() {
+		for t := range results {
+			notUptodate = append(notUptodate, t[0])
+			toUpgrade = append(toUpgrade, t[1])
+			wg.Done()
+		}
+	}()
+
 	// Grab all the installed ones, see if they are eligible for update
 	for _, p := range s.Installed() {
-		available, err := universe.FindPackageVersions(p)
-		if err != nil {
-			removed = append(removed, p)
-		}
-		if len(available) == 0 {
-			continue
-		}
-
-		bestmatch := available.Best(nil)
-		// Found a better version available
-		if !bestmatch.Matches(p) {
-			notUptodate = append(notUptodate, p)
-			toUpgrade = append(toUpgrade, bestmatch)
-		}
+		all <- p
 	}
 
+	close(all)
+	wg.Wait()
+
 	// resolve to packages from the db to be able to encode correctly
 	oldPackages, err := s.getList(universe, notUptodate)
 	if err != nil {
@@ -584,29 +658,54 @@ func (s *Parallel) BuildFormula() (bf.Formula, error) {
 	if err != nil {
 		return nil, err
 	}
-	for _, wanted := range s.Wanted {
-		encodedW, err := wanted.Encode(s.ParallelDatabase)
-		if err != nil {
-			return nil, err
-		}
-		W := bf.Var(encodedW)
-		installedWorld := s.Installed()
-		//TODO:Optimize
-		if len(installedWorld) == 0 {
-			formulas = append(formulas, W) //bf.And(bf.True, W))
-			continue
-		}
 
-		for _, installed := range installedWorld {
-			encodedI, err := installed.Encode(s.ParallelDatabase)
-			if err != nil {
-				return nil, err
+	var wg = new(sync.WaitGroup)
+
+	all := make(chan pkg.Package)
+	results := make(chan bf.Formula, 1)
+	for i := 0; i < s.Concurrency; i++ {
+		wg.Add(1)
+		go func(wg *sync.WaitGroup, c <-chan pkg.Package) {
+			//defer wg.Done()
+			for wanted := range c {
+				encodedW, err := wanted.Encode(s.ParallelDatabase)
+				if err != nil {
+					panic(err)
+				}
+				W := bf.Var(encodedW)
+				installedWorld := s.Installed()
+				//TODO:Optimize
+				if len(installedWorld) == 0 {
+					results <- W
+					continue
+				}
+
+				for _, installed := range installedWorld {
+					encodedI, err := installed.Encode(s.ParallelDatabase)
+					if err != nil {
+						panic(err)
+					}
+					I := bf.Var(encodedI)
+					results <- bf.And(W, I)
+				}
 			}
-			I := bf.Var(encodedI)
-			formulas = append(formulas, bf.And(W, I))
-		}
-
+		}(wg, all)
 	}
+
+	go func() {
+		for t := range results {
+			formulas = append(formulas, t)
+			wg.Done()
+		}
+	}()
+
+	for _, wanted := range s.Wanted {
+		all <- wanted
+	}
+
+	close(all)
+	wg.Wait()
+
 	formulas = append(formulas, r)
 
 	return bf.And(formulas...), nil